Dispersión del intervalo QT corregido como predictor de arritmias ventriculares en el infarto agudo del miocardio / Dispersion of the corrected QT interval as a predictor of ventricular arrhythmias in acute myocardial infarction

RESUMEN Fundamento: La dispersión del intervalo QT es un marcador electrocardiográfico que puede resultar útil en la estratificación de riesgo arrítmicos en pacientes con infarto agudo del miocardio. Objetivo: Describir la influencia de la dispersión del intervalo QT corregido en asociación a otros factores de riesgo como predictores de arritmias ventriculares en el infarto agudo del miocardio con elevación del segmento ST. Metodología: Se estudiaron de menera prospectiva 209 pacientes que ingresaron de forma consecutiva con diagnóstico de infarto agudo de miocardio con elevación del segmento ST de enero de 2013 a junio de 2014 en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus. Se recogieron datos clínicos, de laboratorio electrocardiográficos y ecocardiográficos; se determinó la implicación pronóstica de la dispersión del intervalo QT corregido en la aparición de arritmias ventriculares a través de la regresión logística binaria y las curvas de operador-receptor. Resultados: Las arritmias ventriculares se presentaron en 39 (18.7 %) pacientes. La dispersión del QT corregido mostró una adecuada capacidad de discriminación en la predicción de cualquier episodio arrítmico ventricular grave (c=0.768, p=0.0001). En el análisis multivariado la dispersión del QT resultó un predictor independiente de arritmias ventriculares (OR= 7.075; IC 95%= 1.6- 32.9; p=0.009). Conclusiones: La probabilidad de presentar arritmias ventriculares durante el infarto agudo del miocardio es mayor cuando se incrementan la dispersión del intervalo QT, por lo que se sugiere debe ser una variable a evaluar en la estratificación pronostica del infarto agudo del miocardio.

ABSTRACT Background: Dispersion of the QT interval is an electrocardiographic marker that can be useful in the stratification of arrhythmic risk in patients with acute myocardial infarction. Objective: To describe the influence of corrected QT interval dispersion in association with other risk factors as predictors of ventricular arrhythmias in acute myocardial infarction with ST-segment elevation. Methodology: 209 patients who entered consecutively with diagnosis of acute myocardial infarction with elevation of the ST segment from January 2013 to June 2014 at Camilo Cienfuegos General Provincial Hospital of Sancti Spíritus were studied prospectively. Clinical, electrocardiographic and echocardiographic laboratory data were collected; the prognostic implication of the corrected QT interval dispersion in the appearance of ventricular arrhythmias through binary logistic regression and operator-receiver curves was determined. Results: Ventricular arrhythmias occurred in 39 (18.7%) patients. The dispersion of the corrected QT showed an adequate discrimination capacity in the prediction of any serious ventricular arrhythmic episode (c = 0.768, p = 0.0001). In the multivariate analysis, QT dispersion was an independent predictor of ventricular arrhythmias (OR = 7.075, 95% CI = 1.6-32.9, p = 0.009). Conclusions: The probability of presenting ventricular arrhythmias during acute myocardial infarction is greater when the dispersion of the QT interval is increased, so it is suggested that it should be a variable to be evaluated in the prognostic stratification of acute myocardial infarction.

Advances in Diagnosis and Treatment of Primary Sclerosing Cholangitis / 胃肠病学

Primary sclerosing cholangitis (PSC)is a chronic cholestatic liver disease characterized by inflammation, fibrosis,and stricture of the intra- and/ or extrahepatic bile ducts. PSC is frequently insidious onset,but may aggravate progressively and ultimately leading to biliary cirrhosis and eventually hepatic failure. Most of the PSC patients are associated with inflammatory bowel disease,and the risk of hepatobiliary malignancy especially cholangiocarcinoma increases significantly. So far,the mechanism of PSC is not clearly known and lacking effective medical therapy. This article provides a comprehensive review on advances in diagnosis and treatment of PSC,including the consensus on imaging diagnosis,prognostic stratification and new drugs in ongoing trials.

Value of Red Cell Distribution Width in the Prognosis of Patients with Multiple Myeloma / 现代检验医学杂志

Objective To investigate the relationship between red blood cell distribution width (RDW) and prognosis in patients with multiple myeloma (MM).Methods The population that studied consisted of 27 patients with multiple myeloma and 30 healthy controls.The RDW was calculated according to the results of blood routine examination and compared between patients and healthy controls.Then,compared the difference between the two groups of RDW.MM patients were treated with international standard staging (ISS),and the differences of RDW in different stages were analyzed.ISS staging was used to draw the receiver operating curve (receiver operating characteristic curve,ROC curve),then take RDW14.65 ％ as the best cut-off point,the MM patients were divided into low RDW group (RDW=14.65 ％) and high RDW group (RDW ＞14.65％).Overall survival (OS) condition were compared between the above two groups.The impacts of RDW on OS were analyzed by Kaplan-Meier and Log-rank test.Results The average RDW value in experimental and controlled were 15.60 ％ ± 2.35 ％ vs 12.72 ％ ±0.61 ％ separately (t=6.201,P＜0.001),with statistical differences.The average RDW value in low ISS(Ⅰ + Ⅱ stage) and high ISS (Ⅲ stage) were 13.99 ％ ± 1.08％ vs 16.55 ％±2.39％ separately (t=3.800,P=0.001).The median survival time of low RDW and high RDW group was 13 months and 8 months respectively,and the difference was statistically significant (x2=6.481,P =0.011).Conclusion RDW increased in patients with MM,the risk stratification higher prognosis is worse.

Clinical prognosis in BRAF-mutated PTC

BRAF mutation has recently emerged as a potential prognostic marker for papillary thyroid carcinoma (PTC) due to several studies suggesting that it may condition the development of tumors with aggressive behavior. A study of the phenotypes of thyroid follicular cell lines and transgenic mice characterized by targeted expression of BRAF mutation indicates that, at variance with RET/PTC rearrangement, it induces or facilitates genomic instability and higher invasiveness and eventually deeper tumor de-differentiation and more significant suppression of apoptosis. An analysis of differential gene expression of PTCs harboring BRAF mutation versus PTCs characterized by other genetic alterations shows an important impairment of the expression of genes related to intra-thyroidal iodine metabolism machinery, up-regulation of Glut-1 mRNA, methylation-induced gene silencing of tumor suppressor genes and up-regulation of pro-angiogenetic proteins such as VEGF. Correlation of BRAF mutation with PTC clinico-pathological features yields controversial results, with several studies showing the association with unfavourable clinico-pathological qualities, while others do not confirm the findings. This review will summarize the studies in favor of or in contrast with a role of BRAF mutation as a prognostic marker in PTC. We will also indicate what information we still need in order to routinely introduce this indicator in clinical practice.

Mutações no BRAF surgiram recentemente como potenciais marcadores prognósticos do carcinoma papílifero de tiróide (CPT) graças a vários estudos que sugerem que ele possa condicionar o desenvolvimento de tumores com comportamento agressivo. Um estudo do fenótipo das células de linhagem folicular de tiróide em camundongos transgênicos caracterizados pela expressão direcionada de mutações BRAF, indicam, à semelhança dos rearranjos RET/PTC, que ele induz ou facilita a instabilidade genômica, a alta invasividade e, por fim, uma profunda desdiferenciação tumoral com supressão mais significativa da apoptose. Uma análise da expressão gênica diferencial do CPT associado com mutações BRAF versus o CPT caracterizado por outras alterações gênicas mostra uma redução importante da expressão dos genes relacionados com a maquinaria do metabolismo do iodo intratiroideano, aumento da regulação do mRNA do Glut-1, silenciamento gênico induzido por metilação dos genes supressores tumorais e aumento da regulação das proteínas pró-angiogênicas, como a VEGF. A correlação da mutação BRAF com os achados clínico-patológicos do CPT mostra resultados controversos, com vários estudos indicando associação com parâmetros clínico-patológicos desfavoráveis e outros não confirmando esses achados. Esta revisão sumariza os estudos a favor ou não do papel da mutação BRAF como um marcador prognóstico no CPT. Indicaremos, também, quais informações são ainda necessárias para a introdução rotineira deste indicador na prática clínica.